为阐明PsPⅡ基因与牡丹花芽休眠解除的关系,选用山东菏泽牡丹基地4年生牡丹(Paeoniasuffruticosa)′鲁荷红′健壮植株的花芽,获得了PsPⅡ基因的全长,在不同低温时间处理下研究PsPⅡ基因的表达变化及植株的生理生化变化.结果表明,通过拼接得到899 bp的PsPⅡ全长cDNA.其中,5′非编码区(UTR)为70 bp,3'UTR为226 bp,包括24个碱基的poly(A)尾,含有一个603 bp的完整的ORF,编码200个氨基酸；对PsPⅡ全长cDNA进行生物信息学分析,预测牡丹PⅡ蛋白是一种亲水蛋白,而且与谷氨酰胺合成酶的功能密切相关;同源性分析得出,与牡丹PⅡ蛋白同源性最高的是水稻的PⅡ类蛋白,同源性达83.6％,其次为烟草、拟南芥和松树.实时荧光定量PCR分析结果显示,随着感受低温天数的增加,在整个牡丹内休眠解除的进程中,PsPⅡ基因的表达量不断增加,当低温处理15d时,该基因的表达量达到最高；相关分析表明,PsPⅡ基因表达水平与α-淀粉水解酶、谷氨酰胺合成酶、可溶性碳水化合物含量均呈显著正相关,表明PsPⅡ在牡丹花芽休眠解除过程中的作用是通过影响酶活性参与休眠解除过程中营养物质的代谢.%In order to investigate the relationship between PsP Ⅱ gene and dormancy release by low temperature, using tree peony (Paeonia suffruticosa) 'Lu He Hong' as plant materials, the full length of PsP Ⅱ, bioinformatics analysis and expression pattern were conducted under different chilling treatments. The main results were as follows: The full-length cDNA was 899 bp, containing an open reading frame of 603 bp, which encoded a 200 amino acid polypeptide. Its 5' untranslated regions was 70 bp, 3' UTR was 226 bp, including a 24 bp poly (A) tail. It was predicted that P Ⅱ protein of tree peony was non-secretory hydrophilic protein, modulating the activity of glutamine synthetase. Homology and phylogenetic relationships analysis revealed that P Ⅱ protein in rice was on the same branch with P Ⅱ protein in tree peony and there was an identity ofrn83.6% at amino acid homology. The following species were Nicotiana tabacum, Arabidopsis Thaliana and Pinus pinaster, respectively. By Real-time PCR, we demonstrated that the expression of PsP Ⅱ was enhanced and continuously increased in the buds of tree peony during the release of dormancy by chilling treatment, reaching the highest value during 15 days chilling treatment. Significant positive correlation between the expression level of PsP Ⅱ and α-starch hydrolytic enzymes, the activity of glutamine synthase and soluble carbohydrate was observed. This result indicted that the role of PsPⅡ was to increase the activity of enzymes associated with nutrient metabolism during the process of dormancy release.
展开▼
